Title: Influence of Immersion Vibration on the Void System of Air-Entrained Concrete

Author(s): M. J. Simon, R. B. Jenkins, and K. C. Hover

Publication: Symposium Paper

Volume: 131

Issue:

Appears on pages(s): 99-126

Keywords: air-entrained concretes; air entrainment; consolidation; freeze-thaw durability; fresh concrete; tests; vibration; voids; Materials Research

DOI: 10.14359/1203

Date: 3/1/1992

Abstract:
Experiments were conducted to determine the influence of immersion vibration on the air-void system parameters of air-entrained concrete, as a function of both radial distance and depth from the point of vibrator insertion. For a 1½ in. (40 mm) diameter immersion vibrator, one could conclude that vibration has little or no effect on air-void systems at distances of 5, 8, or 10 in. (125, 200, or 250 mm) from the point of insertion. The same vibrator in the same concrete can reduce the total air content by 50 percent, and increase specific surface by as much as 100 percent directly at the point of vibrator insertion. Which particular effect one may observe in hardened concrete, therefore, depends on the selection of core location relative to point of vibrator insertion. These observations have implications for specifying, casting, and testing air-entrained concrete.